1 // SPDX-License-Identifier: GPL-2.0
5 * Portions Copyright (C) 2020 Christoph Hellwig
8 #include <linux/module.h>
9 #include <linux/ctype.h>
11 #include <linux/genhd.h>
12 #include <linux/kdev_t.h>
13 #include <linux/kernel.h>
14 #include <linux/blkdev.h>
15 #include <linux/backing-dev.h>
16 #include <linux/init.h>
17 #include <linux/spinlock.h>
18 #include <linux/proc_fs.h>
19 #include <linux/seq_file.h>
20 #include <linux/slab.h>
21 #include <linux/kmod.h>
22 #include <linux/major.h>
23 #include <linux/mutex.h>
24 #include <linux/idr.h>
25 #include <linux/log2.h>
26 #include <linux/pm_runtime.h>
27 #include <linux/badblocks.h>
30 #include "blk-rq-qos.h"
32 static struct kobject *block_depr;
35 * Unique, monotonically increasing sequential number associated with block
36 * devices instances (i.e. incremented each time a device is attached).
37 * Associating uevents with block devices in userspace is difficult and racy:
38 * the uevent netlink socket is lossy, and on slow and overloaded systems has
39 * a very high latency.
40 * Block devices do not have exclusive owners in userspace, any process can set
41 * one up (e.g. loop devices). Moreover, device names can be reused (e.g. loop0
42 * can be reused again and again).
43 * A userspace process setting up a block device and watching for its events
44 * cannot thus reliably tell whether an event relates to the device it just set
45 * up or another earlier instance with the same name.
46 * This sequential number allows userspace processes to solve this problem, and
47 * uniquely associate an uevent to the lifetime to a device.
49 static atomic64_t diskseq;
51 /* for extended dynamic devt allocation, currently only one major is used */
52 #define NR_EXT_DEVT (1 << MINORBITS)
53 static DEFINE_IDA(ext_devt_ida);
55 void set_capacity(struct gendisk *disk, sector_t sectors)
57 struct block_device *bdev = disk->part0;
59 spin_lock(&bdev->bd_size_lock);
60 i_size_write(bdev->bd_inode, (loff_t)sectors << SECTOR_SHIFT);
61 spin_unlock(&bdev->bd_size_lock);
63 EXPORT_SYMBOL(set_capacity);
66 * Set disk capacity and notify if the size is not currently zero and will not
67 * be set to zero. Returns true if a uevent was sent, otherwise false.
69 bool set_capacity_and_notify(struct gendisk *disk, sector_t size)
71 sector_t capacity = get_capacity(disk);
72 char *envp[] = { "RESIZE=1", NULL };
74 set_capacity(disk, size);
77 * Only print a message and send a uevent if the gendisk is user visible
78 * and alive. This avoids spamming the log and udev when setting the
79 * initial capacity during probing.
81 if (size == capacity ||
83 (disk->flags & GENHD_FL_HIDDEN))
86 pr_info("%s: detected capacity change from %lld to %lld\n",
87 disk->disk_name, capacity, size);
90 * Historically we did not send a uevent for changes to/from an empty
93 if (!capacity || !size)
95 kobject_uevent_env(&disk_to_dev(disk)->kobj, KOBJ_CHANGE, envp);
98 EXPORT_SYMBOL_GPL(set_capacity_and_notify);
101 * Format the device name of the indicated block device into the supplied buffer
102 * and return a pointer to that same buffer for convenience.
104 * Note: do not use this in new code, use the %pg specifier to sprintf and
107 const char *bdevname(struct block_device *bdev, char *buf)
109 struct gendisk *hd = bdev->bd_disk;
110 int partno = bdev->bd_partno;
113 snprintf(buf, BDEVNAME_SIZE, "%s", hd->disk_name);
114 else if (isdigit(hd->disk_name[strlen(hd->disk_name)-1]))
115 snprintf(buf, BDEVNAME_SIZE, "%sp%d", hd->disk_name, partno);
117 snprintf(buf, BDEVNAME_SIZE, "%s%d", hd->disk_name, partno);
121 EXPORT_SYMBOL(bdevname);
123 static void part_stat_read_all(struct block_device *part,
124 struct disk_stats *stat)
128 memset(stat, 0, sizeof(struct disk_stats));
129 for_each_possible_cpu(cpu) {
130 struct disk_stats *ptr = per_cpu_ptr(part->bd_stats, cpu);
133 for (group = 0; group < NR_STAT_GROUPS; group++) {
134 stat->nsecs[group] += ptr->nsecs[group];
135 stat->sectors[group] += ptr->sectors[group];
136 stat->ios[group] += ptr->ios[group];
137 stat->merges[group] += ptr->merges[group];
140 stat->io_ticks += ptr->io_ticks;
144 static unsigned int part_in_flight(struct block_device *part)
146 unsigned int inflight = 0;
149 for_each_possible_cpu(cpu) {
150 inflight += part_stat_local_read_cpu(part, in_flight[0], cpu) +
151 part_stat_local_read_cpu(part, in_flight[1], cpu);
153 if ((int)inflight < 0)
159 static void part_in_flight_rw(struct block_device *part,
160 unsigned int inflight[2])
166 for_each_possible_cpu(cpu) {
167 inflight[0] += part_stat_local_read_cpu(part, in_flight[0], cpu);
168 inflight[1] += part_stat_local_read_cpu(part, in_flight[1], cpu);
170 if ((int)inflight[0] < 0)
172 if ((int)inflight[1] < 0)
177 * Can be deleted altogether. Later.
180 #define BLKDEV_MAJOR_HASH_SIZE 255
181 static struct blk_major_name {
182 struct blk_major_name *next;
185 void (*probe)(dev_t devt);
186 } *major_names[BLKDEV_MAJOR_HASH_SIZE];
187 static DEFINE_MUTEX(major_names_lock);
188 static DEFINE_SPINLOCK(major_names_spinlock);
190 /* index in the above - for now: assume no multimajor ranges */
191 static inline int major_to_index(unsigned major)
193 return major % BLKDEV_MAJOR_HASH_SIZE;
196 #ifdef CONFIG_PROC_FS
197 void blkdev_show(struct seq_file *seqf, off_t offset)
199 struct blk_major_name *dp;
201 spin_lock(&major_names_spinlock);
202 for (dp = major_names[major_to_index(offset)]; dp; dp = dp->next)
203 if (dp->major == offset)
204 seq_printf(seqf, "%3d %s\n", dp->major, dp->name);
205 spin_unlock(&major_names_spinlock);
207 #endif /* CONFIG_PROC_FS */
210 * __register_blkdev - register a new block device
212 * @major: the requested major device number [1..BLKDEV_MAJOR_MAX-1]. If
213 * @major = 0, try to allocate any unused major number.
214 * @name: the name of the new block device as a zero terminated string
215 * @probe: allback that is called on access to any minor number of @major
217 * The @name must be unique within the system.
219 * The return value depends on the @major input parameter:
221 * - if a major device number was requested in range [1..BLKDEV_MAJOR_MAX-1]
222 * then the function returns zero on success, or a negative error code
223 * - if any unused major number was requested with @major = 0 parameter
224 * then the return value is the allocated major number in range
225 * [1..BLKDEV_MAJOR_MAX-1] or a negative error code otherwise
227 * See Documentation/admin-guide/devices.txt for the list of allocated
230 * Use register_blkdev instead for any new code.
232 int __register_blkdev(unsigned int major, const char *name,
233 void (*probe)(dev_t devt))
235 struct blk_major_name **n, *p;
238 mutex_lock(&major_names_lock);
242 for (index = ARRAY_SIZE(major_names)-1; index > 0; index--) {
243 if (major_names[index] == NULL)
248 printk("%s: failed to get major for %s\n",
257 if (major >= BLKDEV_MAJOR_MAX) {
258 pr_err("%s: major requested (%u) is greater than the maximum (%u) for %s\n",
259 __func__, major, BLKDEV_MAJOR_MAX-1, name);
265 p = kmalloc(sizeof(struct blk_major_name), GFP_KERNEL);
273 strlcpy(p->name, name, sizeof(p->name));
275 index = major_to_index(major);
277 spin_lock(&major_names_spinlock);
278 for (n = &major_names[index]; *n; n = &(*n)->next) {
279 if ((*n)->major == major)
286 spin_unlock(&major_names_spinlock);
289 printk("register_blkdev: cannot get major %u for %s\n",
294 mutex_unlock(&major_names_lock);
297 EXPORT_SYMBOL(__register_blkdev);
299 void unregister_blkdev(unsigned int major, const char *name)
301 struct blk_major_name **n;
302 struct blk_major_name *p = NULL;
303 int index = major_to_index(major);
305 mutex_lock(&major_names_lock);
306 spin_lock(&major_names_spinlock);
307 for (n = &major_names[index]; *n; n = &(*n)->next)
308 if ((*n)->major == major)
310 if (!*n || strcmp((*n)->name, name)) {
316 spin_unlock(&major_names_spinlock);
317 mutex_unlock(&major_names_lock);
321 EXPORT_SYMBOL(unregister_blkdev);
323 int blk_alloc_ext_minor(void)
327 idx = ida_alloc_range(&ext_devt_ida, 0, NR_EXT_DEVT - 1, GFP_KERNEL);
333 void blk_free_ext_minor(unsigned int minor)
335 ida_free(&ext_devt_ida, minor);
338 static char *bdevt_str(dev_t devt, char *buf)
340 if (MAJOR(devt) <= 0xff && MINOR(devt) <= 0xff) {
341 char tbuf[BDEVT_SIZE];
342 snprintf(tbuf, BDEVT_SIZE, "%02x%02x", MAJOR(devt), MINOR(devt));
343 snprintf(buf, BDEVT_SIZE, "%-9s", tbuf);
345 snprintf(buf, BDEVT_SIZE, "%03x:%05x", MAJOR(devt), MINOR(devt));
350 void disk_uevent(struct gendisk *disk, enum kobject_action action)
352 struct block_device *part;
356 xa_for_each(&disk->part_tbl, idx, part) {
357 if (bdev_is_partition(part) && !bdev_nr_sectors(part))
359 if (!kobject_get_unless_zero(&part->bd_device.kobj))
363 kobject_uevent(bdev_kobj(part), action);
364 put_device(&part->bd_device);
369 EXPORT_SYMBOL_GPL(disk_uevent);
371 static void disk_scan_partitions(struct gendisk *disk)
373 struct block_device *bdev;
375 if (!get_capacity(disk) || !disk_part_scan_enabled(disk))
378 set_bit(GD_NEED_PART_SCAN, &disk->state);
379 bdev = blkdev_get_by_dev(disk_devt(disk), FMODE_READ, NULL);
381 blkdev_put(bdev, FMODE_READ);
385 * device_add_disk - add disk information to kernel list
386 * @parent: parent device for the disk
387 * @disk: per-device partitioning information
388 * @groups: Additional per-device sysfs groups
390 * This function registers the partitioning information in @disk
393 int device_add_disk(struct device *parent, struct gendisk *disk,
394 const struct attribute_group **groups)
397 struct device *ddev = disk_to_dev(disk);
401 * The disk queue should now be all set with enough information about
402 * the device for the elevator code to pick an adequate default
403 * elevator if one is needed, that is, for devices requesting queue
406 elevator_init_mq(disk->queue);
409 * If the driver provides an explicit major number it also must provide
410 * the number of minors numbers supported, and those will be used to
412 * Otherwise just allocate the device numbers for both the whole device
413 * and all partitions from the extended dev_t space.
416 if (WARN_ON(!disk->minors))
419 if (disk->minors > DISK_MAX_PARTS) {
420 pr_err("block: can't allocate more than %d partitions\n",
422 disk->minors = DISK_MAX_PARTS;
424 if (disk->first_minor + disk->minors > MINORMASK + 1)
427 if (WARN_ON(disk->minors))
430 ret = blk_alloc_ext_minor();
433 disk->major = BLOCK_EXT_MAJOR;
434 disk->first_minor = ret;
435 disk->flags |= GENHD_FL_EXT_DEVT;
438 /* delay uevents, until we scanned partition table */
439 dev_set_uevent_suppress(ddev, 1);
441 ddev->parent = parent;
442 ddev->groups = groups;
443 dev_set_name(ddev, "%s", disk->disk_name);
444 if (!(disk->flags & GENHD_FL_HIDDEN))
445 ddev->devt = MKDEV(disk->major, disk->first_minor);
446 ret = device_add(ddev);
448 goto out_free_ext_minor;
450 ret = disk_alloc_events(disk);
454 if (!sysfs_deprecated) {
455 ret = sysfs_create_link(block_depr, &ddev->kobj,
456 kobject_name(&ddev->kobj));
462 * avoid probable deadlock caused by allocating memory with
463 * GFP_KERNEL in runtime_resume callback of its all ancestor
466 pm_runtime_set_memalloc_noio(ddev, true);
468 ret = blk_integrity_add(disk);
470 goto out_del_block_link;
472 disk->part0->bd_holder_dir =
473 kobject_create_and_add("holders", &ddev->kobj);
474 if (!disk->part0->bd_holder_dir) {
476 goto out_del_integrity;
478 disk->slave_dir = kobject_create_and_add("slaves", &ddev->kobj);
479 if (!disk->slave_dir) {
481 goto out_put_holder_dir;
484 ret = bd_register_pending_holders(disk);
486 goto out_put_slave_dir;
488 ret = blk_register_queue(disk);
490 goto out_put_slave_dir;
492 if (disk->flags & GENHD_FL_HIDDEN) {
494 * Don't let hidden disks show up in /proc/partitions,
495 * and don't bother scanning for partitions either.
497 disk->flags |= GENHD_FL_SUPPRESS_PARTITION_INFO;
498 disk->flags |= GENHD_FL_NO_PART_SCAN;
500 ret = bdi_register(disk->bdi, "%u:%u",
501 disk->major, disk->first_minor);
503 goto out_unregister_queue;
504 bdi_set_owner(disk->bdi, ddev);
505 ret = sysfs_create_link(&ddev->kobj,
506 &disk->bdi->dev->kobj, "bdi");
508 goto out_unregister_bdi;
510 bdev_add(disk->part0, ddev->devt);
511 disk_scan_partitions(disk);
514 * Announce the disk and partitions after all partitions are
515 * created. (for hidden disks uevents remain suppressed forever)
517 dev_set_uevent_suppress(ddev, 0);
518 disk_uevent(disk, KOBJ_ADD);
521 disk_update_readahead(disk);
522 disk_add_events(disk);
526 if (!(disk->flags & GENHD_FL_HIDDEN))
527 bdi_unregister(disk->bdi);
528 out_unregister_queue:
529 blk_unregister_queue(disk);
530 rq_qos_exit(disk->queue);
532 kobject_put(disk->slave_dir);
534 kobject_put(disk->part0->bd_holder_dir);
536 blk_integrity_del(disk);
538 if (!sysfs_deprecated)
539 sysfs_remove_link(block_depr, dev_name(ddev));
543 if (disk->major == BLOCK_EXT_MAJOR)
544 blk_free_ext_minor(disk->first_minor);
545 return WARN_ON_ONCE(ret); /* keep until all callers handle errors */
547 EXPORT_SYMBOL(device_add_disk);
550 * blk_mark_disk_dead - mark a disk as dead
551 * @disk: disk to mark as dead
553 * Mark as disk as dead (e.g. surprise removed) and don't accept any new I/O
556 void blk_mark_disk_dead(struct gendisk *disk)
558 set_bit(GD_DEAD, &disk->state);
559 blk_queue_start_drain(disk->queue);
561 EXPORT_SYMBOL_GPL(blk_mark_disk_dead);
564 * del_gendisk - remove the gendisk
565 * @disk: the struct gendisk to remove
567 * Removes the gendisk and all its associated resources. This deletes the
568 * partitions associated with the gendisk, and unregisters the associated
571 * This is the counter to the respective __device_add_disk() call.
573 * The final removal of the struct gendisk happens when its refcount reaches 0
574 * with put_disk(), which should be called after del_gendisk(), if
575 * __device_add_disk() was used.
577 * Drivers exist which depend on the release of the gendisk to be synchronous,
578 * it should not be deferred.
582 void del_gendisk(struct gendisk *disk)
584 struct request_queue *q = disk->queue;
588 if (WARN_ON_ONCE(!disk_live(disk) && !(disk->flags & GENHD_FL_HIDDEN)))
591 blk_integrity_del(disk);
592 disk_del_events(disk);
594 mutex_lock(&disk->open_mutex);
595 remove_inode_hash(disk->part0->bd_inode);
596 blk_drop_partitions(disk);
597 mutex_unlock(&disk->open_mutex);
599 fsync_bdev(disk->part0);
600 __invalidate_device(disk->part0, true);
605 set_bit(GD_DEAD, &disk->state);
606 set_capacity(disk, 0);
609 * Prevent new I/O from crossing bio_queue_enter().
611 blk_queue_start_drain(q);
613 if (!(disk->flags & GENHD_FL_HIDDEN)) {
614 sysfs_remove_link(&disk_to_dev(disk)->kobj, "bdi");
617 * Unregister bdi before releasing device numbers (as they can
618 * get reused and we'd get clashes in sysfs).
620 bdi_unregister(disk->bdi);
623 blk_unregister_queue(disk);
625 kobject_put(disk->part0->bd_holder_dir);
626 kobject_put(disk->slave_dir);
628 part_stat_set_all(disk->part0, 0);
629 disk->part0->bd_stamp = 0;
630 if (!sysfs_deprecated)
631 sysfs_remove_link(block_depr, dev_name(disk_to_dev(disk)));
632 pm_runtime_set_memalloc_noio(disk_to_dev(disk), false);
633 device_del(disk_to_dev(disk));
635 blk_mq_freeze_queue_wait(q);
639 blk_flush_integrity();
641 * Allow using passthrough request again after the queue is torn down.
643 blk_queue_flag_clear(QUEUE_FLAG_INIT_DONE, q);
644 __blk_mq_unfreeze_queue(q, true);
647 EXPORT_SYMBOL(del_gendisk);
649 /* sysfs access to bad-blocks list. */
650 static ssize_t disk_badblocks_show(struct device *dev,
651 struct device_attribute *attr,
654 struct gendisk *disk = dev_to_disk(dev);
657 return sprintf(page, "\n");
659 return badblocks_show(disk->bb, page, 0);
662 static ssize_t disk_badblocks_store(struct device *dev,
663 struct device_attribute *attr,
664 const char *page, size_t len)
666 struct gendisk *disk = dev_to_disk(dev);
671 return badblocks_store(disk->bb, page, len, 0);
674 void blk_request_module(dev_t devt)
676 unsigned int major = MAJOR(devt);
677 struct blk_major_name **n;
679 mutex_lock(&major_names_lock);
680 for (n = &major_names[major_to_index(major)]; *n; n = &(*n)->next) {
681 if ((*n)->major == major && (*n)->probe) {
683 mutex_unlock(&major_names_lock);
687 mutex_unlock(&major_names_lock);
689 if (request_module("block-major-%d-%d", MAJOR(devt), MINOR(devt)) > 0)
690 /* Make old-style 2.4 aliases work */
691 request_module("block-major-%d", MAJOR(devt));
695 * print a full list of all partitions - intended for places where the root
696 * filesystem can't be mounted and thus to give the victim some idea of what
699 void __init printk_all_partitions(void)
701 struct class_dev_iter iter;
704 class_dev_iter_init(&iter, &block_class, NULL, &disk_type);
705 while ((dev = class_dev_iter_next(&iter))) {
706 struct gendisk *disk = dev_to_disk(dev);
707 struct block_device *part;
708 char devt_buf[BDEVT_SIZE];
712 * Don't show empty devices or things that have been
715 if (get_capacity(disk) == 0 ||
716 (disk->flags & GENHD_FL_SUPPRESS_PARTITION_INFO))
720 * Note, unlike /proc/partitions, I am showing the numbers in
721 * hex - the same format as the root= option takes.
724 xa_for_each(&disk->part_tbl, idx, part) {
725 if (!bdev_nr_sectors(part))
727 printk("%s%s %10llu %pg %s",
728 bdev_is_partition(part) ? " " : "",
729 bdevt_str(part->bd_dev, devt_buf),
730 bdev_nr_sectors(part) >> 1, part,
732 part->bd_meta_info->uuid : "");
733 if (bdev_is_partition(part))
735 else if (dev->parent && dev->parent->driver)
736 printk(" driver: %s\n",
737 dev->parent->driver->name);
739 printk(" (driver?)\n");
743 class_dev_iter_exit(&iter);
746 #ifdef CONFIG_PROC_FS
748 static void *disk_seqf_start(struct seq_file *seqf, loff_t *pos)
751 struct class_dev_iter *iter;
754 iter = kmalloc(sizeof(*iter), GFP_KERNEL);
756 return ERR_PTR(-ENOMEM);
758 seqf->private = iter;
759 class_dev_iter_init(iter, &block_class, NULL, &disk_type);
761 dev = class_dev_iter_next(iter);
766 return dev_to_disk(dev);
769 static void *disk_seqf_next(struct seq_file *seqf, void *v, loff_t *pos)
774 dev = class_dev_iter_next(seqf->private);
776 return dev_to_disk(dev);
781 static void disk_seqf_stop(struct seq_file *seqf, void *v)
783 struct class_dev_iter *iter = seqf->private;
785 /* stop is called even after start failed :-( */
787 class_dev_iter_exit(iter);
789 seqf->private = NULL;
793 static void *show_partition_start(struct seq_file *seqf, loff_t *pos)
797 p = disk_seqf_start(seqf, pos);
798 if (!IS_ERR_OR_NULL(p) && !*pos)
799 seq_puts(seqf, "major minor #blocks name\n\n");
803 static int show_partition(struct seq_file *seqf, void *v)
805 struct gendisk *sgp = v;
806 struct block_device *part;
809 /* Don't show non-partitionable removeable devices or empty devices */
810 if (!get_capacity(sgp) || (!disk_max_parts(sgp) &&
811 (sgp->flags & GENHD_FL_REMOVABLE)))
813 if (sgp->flags & GENHD_FL_SUPPRESS_PARTITION_INFO)
817 xa_for_each(&sgp->part_tbl, idx, part) {
818 if (!bdev_nr_sectors(part))
820 seq_printf(seqf, "%4d %7d %10llu %pg\n",
821 MAJOR(part->bd_dev), MINOR(part->bd_dev),
822 bdev_nr_sectors(part) >> 1, part);
828 static const struct seq_operations partitions_op = {
829 .start = show_partition_start,
830 .next = disk_seqf_next,
831 .stop = disk_seqf_stop,
832 .show = show_partition
836 static int __init genhd_device_init(void)
840 block_class.dev_kobj = sysfs_dev_block_kobj;
841 error = class_register(&block_class);
846 register_blkdev(BLOCK_EXT_MAJOR, "blkext");
848 /* create top-level block dir */
849 if (!sysfs_deprecated)
850 block_depr = kobject_create_and_add("block", NULL);
854 subsys_initcall(genhd_device_init);
856 static ssize_t disk_range_show(struct device *dev,
857 struct device_attribute *attr, char *buf)
859 struct gendisk *disk = dev_to_disk(dev);
861 return sprintf(buf, "%d\n", disk->minors);
864 static ssize_t disk_ext_range_show(struct device *dev,
865 struct device_attribute *attr, char *buf)
867 struct gendisk *disk = dev_to_disk(dev);
869 return sprintf(buf, "%d\n", disk_max_parts(disk));
872 static ssize_t disk_removable_show(struct device *dev,
873 struct device_attribute *attr, char *buf)
875 struct gendisk *disk = dev_to_disk(dev);
877 return sprintf(buf, "%d\n",
878 (disk->flags & GENHD_FL_REMOVABLE ? 1 : 0));
881 static ssize_t disk_hidden_show(struct device *dev,
882 struct device_attribute *attr, char *buf)
884 struct gendisk *disk = dev_to_disk(dev);
886 return sprintf(buf, "%d\n",
887 (disk->flags & GENHD_FL_HIDDEN ? 1 : 0));
890 static ssize_t disk_ro_show(struct device *dev,
891 struct device_attribute *attr, char *buf)
893 struct gendisk *disk = dev_to_disk(dev);
895 return sprintf(buf, "%d\n", get_disk_ro(disk) ? 1 : 0);
898 ssize_t part_size_show(struct device *dev,
899 struct device_attribute *attr, char *buf)
901 return sprintf(buf, "%llu\n", bdev_nr_sectors(dev_to_bdev(dev)));
904 ssize_t part_stat_show(struct device *dev,
905 struct device_attribute *attr, char *buf)
907 struct block_device *bdev = dev_to_bdev(dev);
908 struct request_queue *q = bdev->bd_disk->queue;
909 struct disk_stats stat;
910 unsigned int inflight;
912 part_stat_read_all(bdev, &stat);
914 inflight = blk_mq_in_flight(q, bdev);
916 inflight = part_in_flight(bdev);
919 "%8lu %8lu %8llu %8u "
920 "%8lu %8lu %8llu %8u "
922 "%8lu %8lu %8llu %8u "
926 stat.merges[STAT_READ],
927 (unsigned long long)stat.sectors[STAT_READ],
928 (unsigned int)div_u64(stat.nsecs[STAT_READ], NSEC_PER_MSEC),
929 stat.ios[STAT_WRITE],
930 stat.merges[STAT_WRITE],
931 (unsigned long long)stat.sectors[STAT_WRITE],
932 (unsigned int)div_u64(stat.nsecs[STAT_WRITE], NSEC_PER_MSEC),
934 jiffies_to_msecs(stat.io_ticks),
935 (unsigned int)div_u64(stat.nsecs[STAT_READ] +
936 stat.nsecs[STAT_WRITE] +
937 stat.nsecs[STAT_DISCARD] +
938 stat.nsecs[STAT_FLUSH],
940 stat.ios[STAT_DISCARD],
941 stat.merges[STAT_DISCARD],
942 (unsigned long long)stat.sectors[STAT_DISCARD],
943 (unsigned int)div_u64(stat.nsecs[STAT_DISCARD], NSEC_PER_MSEC),
944 stat.ios[STAT_FLUSH],
945 (unsigned int)div_u64(stat.nsecs[STAT_FLUSH], NSEC_PER_MSEC));
948 ssize_t part_inflight_show(struct device *dev, struct device_attribute *attr,
951 struct block_device *bdev = dev_to_bdev(dev);
952 struct request_queue *q = bdev->bd_disk->queue;
953 unsigned int inflight[2];
956 blk_mq_in_flight_rw(q, bdev, inflight);
958 part_in_flight_rw(bdev, inflight);
960 return sprintf(buf, "%8u %8u\n", inflight[0], inflight[1]);
963 static ssize_t disk_capability_show(struct device *dev,
964 struct device_attribute *attr, char *buf)
966 struct gendisk *disk = dev_to_disk(dev);
968 return sprintf(buf, "%x\n", disk->flags);
971 static ssize_t disk_alignment_offset_show(struct device *dev,
972 struct device_attribute *attr,
975 struct gendisk *disk = dev_to_disk(dev);
977 return sprintf(buf, "%d\n", queue_alignment_offset(disk->queue));
980 static ssize_t disk_discard_alignment_show(struct device *dev,
981 struct device_attribute *attr,
984 struct gendisk *disk = dev_to_disk(dev);
986 return sprintf(buf, "%d\n", queue_discard_alignment(disk->queue));
989 static ssize_t diskseq_show(struct device *dev,
990 struct device_attribute *attr, char *buf)
992 struct gendisk *disk = dev_to_disk(dev);
994 return sprintf(buf, "%llu\n", disk->diskseq);
997 static DEVICE_ATTR(range, 0444, disk_range_show, NULL);
998 static DEVICE_ATTR(ext_range, 0444, disk_ext_range_show, NULL);
999 static DEVICE_ATTR(removable, 0444, disk_removable_show, NULL);
1000 static DEVICE_ATTR(hidden, 0444, disk_hidden_show, NULL);
1001 static DEVICE_ATTR(ro, 0444, disk_ro_show, NULL);
1002 static DEVICE_ATTR(size, 0444, part_size_show, NULL);
1003 static DEVICE_ATTR(alignment_offset, 0444, disk_alignment_offset_show, NULL);
1004 static DEVICE_ATTR(discard_alignment, 0444, disk_discard_alignment_show, NULL);
1005 static DEVICE_ATTR(capability, 0444, disk_capability_show, NULL);
1006 static DEVICE_ATTR(stat, 0444, part_stat_show, NULL);
1007 static DEVICE_ATTR(inflight, 0444, part_inflight_show, NULL);
1008 static DEVICE_ATTR(badblocks, 0644, disk_badblocks_show, disk_badblocks_store);
1009 static DEVICE_ATTR(diskseq, 0444, diskseq_show, NULL);
1011 #ifdef CONFIG_FAIL_MAKE_REQUEST
1012 ssize_t part_fail_show(struct device *dev,
1013 struct device_attribute *attr, char *buf)
1015 return sprintf(buf, "%d\n", dev_to_bdev(dev)->bd_make_it_fail);
1018 ssize_t part_fail_store(struct device *dev,
1019 struct device_attribute *attr,
1020 const char *buf, size_t count)
1024 if (count > 0 && sscanf(buf, "%d", &i) > 0)
1025 dev_to_bdev(dev)->bd_make_it_fail = i;
1030 static struct device_attribute dev_attr_fail =
1031 __ATTR(make-it-fail, 0644, part_fail_show, part_fail_store);
1032 #endif /* CONFIG_FAIL_MAKE_REQUEST */
1034 #ifdef CONFIG_FAIL_IO_TIMEOUT
1035 static struct device_attribute dev_attr_fail_timeout =
1036 __ATTR(io-timeout-fail, 0644, part_timeout_show, part_timeout_store);
1039 static struct attribute *disk_attrs[] = {
1040 &dev_attr_range.attr,
1041 &dev_attr_ext_range.attr,
1042 &dev_attr_removable.attr,
1043 &dev_attr_hidden.attr,
1045 &dev_attr_size.attr,
1046 &dev_attr_alignment_offset.attr,
1047 &dev_attr_discard_alignment.attr,
1048 &dev_attr_capability.attr,
1049 &dev_attr_stat.attr,
1050 &dev_attr_inflight.attr,
1051 &dev_attr_badblocks.attr,
1052 &dev_attr_events.attr,
1053 &dev_attr_events_async.attr,
1054 &dev_attr_events_poll_msecs.attr,
1055 &dev_attr_diskseq.attr,
1056 #ifdef CONFIG_FAIL_MAKE_REQUEST
1057 &dev_attr_fail.attr,
1059 #ifdef CONFIG_FAIL_IO_TIMEOUT
1060 &dev_attr_fail_timeout.attr,
1065 static umode_t disk_visible(struct kobject *kobj, struct attribute *a, int n)
1067 struct device *dev = container_of(kobj, typeof(*dev), kobj);
1068 struct gendisk *disk = dev_to_disk(dev);
1070 if (a == &dev_attr_badblocks.attr && !disk->bb)
1075 static struct attribute_group disk_attr_group = {
1076 .attrs = disk_attrs,
1077 .is_visible = disk_visible,
1080 static const struct attribute_group *disk_attr_groups[] = {
1086 * disk_release - releases all allocated resources of the gendisk
1087 * @dev: the device representing this disk
1089 * This function releases all allocated resources of the gendisk.
1091 * Drivers which used __device_add_disk() have a gendisk with a request_queue
1092 * assigned. Since the request_queue sits on top of the gendisk for these
1093 * drivers we also call blk_put_queue() for them, and we expect the
1094 * request_queue refcount to reach 0 at this point, and so the request_queue
1095 * will also be freed prior to the disk.
1097 * Context: can sleep
1099 static void disk_release(struct device *dev)
1101 struct gendisk *disk = dev_to_disk(dev);
1104 WARN_ON_ONCE(disk_live(disk));
1106 blk_mq_cancel_work_sync(disk->queue);
1108 disk_release_events(disk);
1109 kfree(disk->random);
1110 xa_destroy(&disk->part_tbl);
1111 disk->queue->disk = NULL;
1112 blk_put_queue(disk->queue);
1113 iput(disk->part0->bd_inode); /* frees the disk */
1116 static int block_uevent(struct device *dev, struct kobj_uevent_env *env)
1118 struct gendisk *disk = dev_to_disk(dev);
1120 return add_uevent_var(env, "DISKSEQ=%llu", disk->diskseq);
1123 struct class block_class = {
1125 .dev_uevent = block_uevent,
1128 static char *block_devnode(struct device *dev, umode_t *mode,
1129 kuid_t *uid, kgid_t *gid)
1131 struct gendisk *disk = dev_to_disk(dev);
1133 if (disk->fops->devnode)
1134 return disk->fops->devnode(disk, mode);
1138 const struct device_type disk_type = {
1140 .groups = disk_attr_groups,
1141 .release = disk_release,
1142 .devnode = block_devnode,
1145 #ifdef CONFIG_PROC_FS
1147 * aggregate disk stat collector. Uses the same stats that the sysfs
1148 * entries do, above, but makes them available through one seq_file.
1150 * The output looks suspiciously like /proc/partitions with a bunch of
1153 static int diskstats_show(struct seq_file *seqf, void *v)
1155 struct gendisk *gp = v;
1156 struct block_device *hd;
1157 unsigned int inflight;
1158 struct disk_stats stat;
1162 if (&disk_to_dev(gp)->kobj.entry == block_class.devices.next)
1163 seq_puts(seqf, "major minor name"
1164 " rio rmerge rsect ruse wio wmerge "
1165 "wsect wuse running use aveq"
1170 xa_for_each(&gp->part_tbl, idx, hd) {
1171 if (bdev_is_partition(hd) && !bdev_nr_sectors(hd))
1173 part_stat_read_all(hd, &stat);
1174 if (queue_is_mq(gp->queue))
1175 inflight = blk_mq_in_flight(gp->queue, hd);
1177 inflight = part_in_flight(hd);
1179 seq_printf(seqf, "%4d %7d %pg "
1186 MAJOR(hd->bd_dev), MINOR(hd->bd_dev), hd,
1187 stat.ios[STAT_READ],
1188 stat.merges[STAT_READ],
1189 stat.sectors[STAT_READ],
1190 (unsigned int)div_u64(stat.nsecs[STAT_READ],
1192 stat.ios[STAT_WRITE],
1193 stat.merges[STAT_WRITE],
1194 stat.sectors[STAT_WRITE],
1195 (unsigned int)div_u64(stat.nsecs[STAT_WRITE],
1198 jiffies_to_msecs(stat.io_ticks),
1199 (unsigned int)div_u64(stat.nsecs[STAT_READ] +
1200 stat.nsecs[STAT_WRITE] +
1201 stat.nsecs[STAT_DISCARD] +
1202 stat.nsecs[STAT_FLUSH],
1204 stat.ios[STAT_DISCARD],
1205 stat.merges[STAT_DISCARD],
1206 stat.sectors[STAT_DISCARD],
1207 (unsigned int)div_u64(stat.nsecs[STAT_DISCARD],
1209 stat.ios[STAT_FLUSH],
1210 (unsigned int)div_u64(stat.nsecs[STAT_FLUSH],
1219 static const struct seq_operations diskstats_op = {
1220 .start = disk_seqf_start,
1221 .next = disk_seqf_next,
1222 .stop = disk_seqf_stop,
1223 .show = diskstats_show
1226 static int __init proc_genhd_init(void)
1228 proc_create_seq("diskstats", 0, NULL, &diskstats_op);
1229 proc_create_seq("partitions", 0, NULL, &partitions_op);
1232 module_init(proc_genhd_init);
1233 #endif /* CONFIG_PROC_FS */
1235 dev_t part_devt(struct gendisk *disk, u8 partno)
1237 struct block_device *part;
1241 part = xa_load(&disk->part_tbl, partno);
1243 devt = part->bd_dev;
1249 dev_t blk_lookup_devt(const char *name, int partno)
1251 dev_t devt = MKDEV(0, 0);
1252 struct class_dev_iter iter;
1255 class_dev_iter_init(&iter, &block_class, NULL, &disk_type);
1256 while ((dev = class_dev_iter_next(&iter))) {
1257 struct gendisk *disk = dev_to_disk(dev);
1259 if (strcmp(dev_name(dev), name))
1262 if (partno < disk->minors) {
1263 /* We need to return the right devno, even
1264 * if the partition doesn't exist yet.
1266 devt = MKDEV(MAJOR(dev->devt),
1267 MINOR(dev->devt) + partno);
1269 devt = part_devt(disk, partno);
1274 class_dev_iter_exit(&iter);
1278 struct gendisk *__alloc_disk_node(struct request_queue *q, int node_id,
1279 struct lock_class_key *lkclass)
1281 struct gendisk *disk;
1283 if (!blk_get_queue(q))
1286 disk = kzalloc_node(sizeof(struct gendisk), GFP_KERNEL, node_id);
1290 disk->bdi = bdi_alloc(node_id);
1294 disk->part0 = bdev_alloc(disk, 0);
1298 disk->node_id = node_id;
1299 mutex_init(&disk->open_mutex);
1300 xa_init(&disk->part_tbl);
1301 if (xa_insert(&disk->part_tbl, 0, disk->part0, GFP_KERNEL))
1302 goto out_destroy_part_tbl;
1304 rand_initialize_disk(disk);
1305 disk_to_dev(disk)->class = &block_class;
1306 disk_to_dev(disk)->type = &disk_type;
1307 device_initialize(disk_to_dev(disk));
1311 lockdep_init_map(&disk->lockdep_map, "(bio completion)", lkclass, 0);
1312 #ifdef CONFIG_BLOCK_HOLDER_DEPRECATED
1313 INIT_LIST_HEAD(&disk->slave_bdevs);
1317 out_destroy_part_tbl:
1318 xa_destroy(&disk->part_tbl);
1319 disk->part0->bd_disk = NULL;
1320 iput(disk->part0->bd_inode);
1329 EXPORT_SYMBOL(__alloc_disk_node);
1331 struct gendisk *__blk_alloc_disk(int node, struct lock_class_key *lkclass)
1333 struct request_queue *q;
1334 struct gendisk *disk;
1336 q = blk_alloc_queue(node);
1340 disk = __alloc_disk_node(q, node, lkclass);
1342 blk_cleanup_queue(q);
1347 EXPORT_SYMBOL(__blk_alloc_disk);
1350 * put_disk - decrements the gendisk refcount
1351 * @disk: the struct gendisk to decrement the refcount for
1353 * This decrements the refcount for the struct gendisk. When this reaches 0
1354 * we'll have disk_release() called.
1356 * Context: Any context, but the last reference must not be dropped from
1359 void put_disk(struct gendisk *disk)
1362 put_device(disk_to_dev(disk));
1364 EXPORT_SYMBOL(put_disk);
1367 * blk_cleanup_disk - shutdown a gendisk allocated by blk_alloc_disk
1368 * @disk: gendisk to shutdown
1370 * Mark the queue hanging off @disk DYING, drain all pending requests, then mark
1371 * the queue DEAD, destroy and put it and the gendisk structure.
1373 * Context: can sleep
1375 void blk_cleanup_disk(struct gendisk *disk)
1377 blk_cleanup_queue(disk->queue);
1380 EXPORT_SYMBOL(blk_cleanup_disk);
1382 static void set_disk_ro_uevent(struct gendisk *gd, int ro)
1384 char event[] = "DISK_RO=1";
1385 char *envp[] = { event, NULL };
1389 kobject_uevent_env(&disk_to_dev(gd)->kobj, KOBJ_CHANGE, envp);
1393 * set_disk_ro - set a gendisk read-only
1394 * @disk: gendisk to operate on
1395 * @read_only: %true to set the disk read-only, %false set the disk read/write
1397 * This function is used to indicate whether a given disk device should have its
1398 * read-only flag set. set_disk_ro() is typically used by device drivers to
1399 * indicate whether the underlying physical device is write-protected.
1401 void set_disk_ro(struct gendisk *disk, bool read_only)
1404 if (test_and_set_bit(GD_READ_ONLY, &disk->state))
1407 if (!test_and_clear_bit(GD_READ_ONLY, &disk->state))
1410 set_disk_ro_uevent(disk, read_only);
1412 EXPORT_SYMBOL(set_disk_ro);
1414 int bdev_read_only(struct block_device *bdev)
1416 return bdev->bd_read_only || get_disk_ro(bdev->bd_disk);
1418 EXPORT_SYMBOL(bdev_read_only);
1420 void inc_diskseq(struct gendisk *disk)
1422 disk->diskseq = atomic64_inc_return(&diskseq);